Sati is practice in Hinduism (not by the ancients), where a widow will place herself within the funeral pyre of her beloved. Though a violent practice that has been dogmatically followed, it nonetheless holds some deep philosophical truths that I have not seen expressed anywhere else.
Sati was not an ancient Hindu practice, but seems to begin at the time of Islamic invaders. The conquering Muslims would invade kingdoms and ask for two things: 1) the temples; and 2) the women. Credit given to these women, they took their lives as opposed to serving a foreign family and a foreign god. Nonetheless, the painful tradition carried on due to harsh patriarchal influences.
In the ancient stories, Shiva is the original masculine. Defined in the ancient tantras as "awareness", Shiva is the bridge between the Para-Brahman "non-awareness" reality, and the material world of samsara. His consort is Shakti, the energy which creates the fabric of space and time for the material world to exist. She is defined in the ancient tantras as "witness" as she is the ability to create linearity and thus, our story-line. From Shakti is the Universe/World created. Because the Universe is her offspring, she also had to dive-in with her children and get lost in samsara, for the sake of saving her children.
Against her father's wishes, Sati comes across Shiva and is completely enamored, I mean love-struck. From here we get the story of Sati's emotional battle between her romantic appeal Shiva and her father Daksha. With Daksha, she is to be the proper daughter as propagated by Brahmanic culture. With Shiva, to be with Shiva, she is to move beyond the cultural norms to recognize her true potential as Shakti, which may includes anti-Brahmanic practices including the panchamakarmas. Nonetheless, to recognize her essence as Shakti, she needed to move beyond the ego identity. However, Sati's situation was too dense where, because of her father's opposition to Shiva, she sacrificed her ego-identity with her inner-fire. Hence, to liberate herself she realized that her ego-identity must be subdued, which would have caused numerous cultural difficulties being the daughter of the propagated of the first three Vedas. She can be either of the world (ego) and provide cultural governance, or she can be the infinite (Self) recognizing that one too must be liberated from the world, from culture.
Overly educated and continuously exploring and revealing more behind the veil.
"It cannot be too highly emphasized that the mystic swims in the same waters in which the psychotic drowns."
-James Wasserman, The Mystery Traditions